Climate Change in the Arctic - The Changing Arctic Environment: The Arctic Messenger - page 242

But getting back to the topic, can the sunspot cycle explain our warming climate?
Variation in solar intensity over the past 30 years can be measured and therefore evaluated
intermsofitspotentialtoexplaincurrentchangesinglobaltemperature.Whenthisisdone,
it is found that the change in energy received by Earth over a complete sunspot cycle is
roughly equivalent to Earth's temperature response to only 15 years' worth of present-day
anthropogenic emissions of carbon dioxide. Clearly, our present climate trends are not be-
ing primarily driven by changes in luminosity.
To conclude this section on attribution, we will listen to the words of IPCC AR5:
“GHGs contributed a global mean surface warming likely to be in the range of 0.5°C to
1.3°Covertheperiod1951-2010withthecontributionsfromotheranthropogenicforcings,
including the cooling effects of aerosols, likely to be in the range of −0.6°C to 0.1°C. The
contribution from natural forcings is likely to be in the range of −0.1°C to 0.1°C, and from
natural internal variability is likely to be in the range of −0.1°C to 0.1°C. Together these
assessed contributions are consistent with the observed warming of approximately 0.6°C to
0.7°C.” They sum it all up with this: “It is extremely likely that human influence has been
the dominant cause of the observed warming since the mid-twentieth century.” 8
The reason I have gone into some depth on global climate attribution and global cli-
mate projections for the future is because I want it to be quite clear that amongst the sci-
entific community, there is absolutely no doubt that our globe is warming and that this is
a response to increasing atmospheric concentrations of anthropogenic GHGs. Furthermore,
it will help clarify what is going on in the Arctic and to explain how a changing Arctic is
very likely to lead to changes elsewhere on the globe. Now that we understand how and
why our global climate is warming, we can move back to the situation in the Arctic.